Design, Synthesis, and Anticancer Studies of a p -Cymene-Ru(II)-Curcumin Organometallic Conjugate Based on a Fluorescent 4-Amino-1,8-naphthalimide Tröger's Base Scaffold.

A unique V-shaped "chiral" supramolecular scaffold, -(4-pyridyl)-4-amino-1,8-naphthalimide Tröger's base (), was synthesized in good yield from a precursor -(4-pyridyl)-4-amino-1,8-naphthalimide (). was characterized using different spectroscopic methods and the molecular structure was elucidated by diffraction analysis. A new -cymene-Ru(II)-curcumin conjugate () was designed by reacting dipyridyl donor and ruthenium-curcuminato acceptor [ (-cymene)Ru-(curcuminato)Cl] in the presence of silver triflate. was isolated in quantitative yield and characterized using Fourier transform infrared (FT-IR), NMR (H, C, and F), and electrospray ionization mass spectrometry (ESI-MS), and the molecular structure has been predicted using a computational study. Both and exhibited intramolecular charge transfer (ICT)-based fluorescence emission. Furthermore, the anticancer properties of , , and were assessed in different cancer cell lines. Gratifyingly, the conjugate displayed fast-cellular internalization and good cytotoxicity against HeLa, HCT-116, and HepG2 cancer cells and the estimated IC value was much lower than that of the precursors ( and and the well-known chemotherapeutic drug cisplatin.